1. Field of the Invention
The present invention relates to a disc drive apparatus for driving an optical disc, and more particularly to a disc drive apparatus equipped with a disc holding mechanism for detachably holding the optical disc thereon.
2. Description of the Related Art
Up until now, there have been proposed a wide variety of conventional disc drive apparatuses each designed to drive an optical disc, such as a compact disc (CD) and a digital versatile disc (DVD), having a central portion formed with a circular hole. The conventional disc drive apparatuses of this kind have so far been available for various information recording and/or reproducing apparatuses. The conventional disc drive apparatuses thus proposed are disclosed in the Japanese Patent Laid-Open Publication No. 10-134462 and the Japanese Patent Laid-Open Publication No. 10-269722.
One typical example of the conventional disc drive apparatuses is raised as a forcible mount type of conventional disc drive apparatus. The conventional disc drive apparatus of this type comprises a disc retaining member formed with a peripheral ledge, a plurality of disc holding members each movably supported by the disc retaining member, and a plurality of spring members each intervening between the disc retaining member and each of the disc holding members to have each of the disc holding members resiliently urged radially outwardly of the disc retaining member. The disc retaining member, the disc holding members and the spring members are collectively constitute a disc holding mechanism for detachably holding the optical disc thereon.
In the conventional disc drive apparatus thus constructed, the optical disc is mounted on the disc retaining member under the state that the central portion of the optical disc is received in the peripheral ledge of the disc retaining member with each of the disc holding members being resiliently urged by each of the spring members radially outwardly of the disc retaining member to have each of the disc holding members held in contact with the central portion of the optical disc to hold the optical disc to the disc retaining member. In this example, the optical disc is forcibly mounted on and dismounted from the disc retaining member against the resilient force of each of the spring members.
Another typical example of the conventional disc drive apparatuses is raised as a mechanical mount type of conventional disc drive apparatus and shown in FIGS. 13 to 16. The conventional disc drive apparatus 900 of this type comprises a frame member 910, a disc retaining member 920 supported by the frame member 910 and rotatable around its rotation axis, a cam member 930 rockably supported by the disc retaining member 920, a plurality of disc holding members 940 each supported by the disc retaining member 920 and operatively coupled with the cam member 930, and a plurality of spring members 950 each intervening between the disc retaining member 920 and each of the disc holding members 940 to have each of the disc holding members 940 resiliently urged radially outwardly of the disc retaining member 920.
The disc retaining member 920 is formed with a peripheral ledge 921 and operative to assume two different operation states including a disc retaining state in which the optical disc, not shown, is mounted on the disc retaining member 920 under the state that the central portion of the optical disc is received in the peripheral ledge 921 of the disc retaining member 920, and a non-retaining state in which the optical disc is dismounted from the disc retaining member 920.
The cam member 930 is rockable with respect to the disc retaining member 920 to assume two different operation positions including a first rocking position shown in FIGS. 16A and 16B, and a second rocking position shown in FIGS. 14A and 14B. The cam member 930 is formed with a plurality of grooves 931 each having opposing side surfaces 931a and 931b opposing and spaced apart from each other at a constant space distance.
Each of the disc holding members 940 has a holding end 941 and is movable with respect to the disc retaining member 920 to assume two different operation positions including a disc holding position in which the holding end 941 of each of the disc holding members 940 is held in contact with the central portion of the optical disc to hold the optical disc to the disc retaining member 920 under the state that the cam member 930 is rocked to assume the first rocking position as shown in FIGS. 16A and 16B, and a disc releasing position in which the holding end 941 of each of the disc holding members 940 is held out of contact with the central portion of the optical disc to release the optical disc from the disc retaining member 920 under the state that the cam member 930 is rocked to assume the second rocking position as shown in FIGS. 14A and 14B.
Each of the disc holding members 940 has a projection 942 received in each of the grooves 931 of the cam member 930 and slidably movable along the opposing side surfaces 931a and 931b of each of the grooves 931 of the cam member 930 to have each of the disc holding members 940 moved between the disc holding position and the disc releasing position. The opposing side surfaces 931a and 931b of each of the grooves 931 of the cam member 930 are spaced apart from each other at the constant space distance approximately equal to the diameter of the projection 942 of each of the disc holding members 940.
Each of the spring members 950 intervenes between the disc retaining member 920 and each of the disc holding members 940 to have each of the disc holding members 940 resiliently urged to assume the disc holding position as shown in FIGS. 16A and 16B.
The disc retaining member 920, the cam member 930, the disc holding members 940 and the spring members 950 are collectively constitute a disc holding mechanism 960 designed to detachably hold the optical disc thereon.
The conventional disc drive apparatus 900 further comprises a cam rocking member 970 movably supported by the frame member 910, an optical pickup unit 980 for recording information to and reproducing information from the optical disc, and a changeover lever 990 operatively connected to the cam rocking member 970.
The cam rocking member 970 is movable with respect to the frame member 910 to assume two different operation positions including an engaging position in which the cam rocking member 970 is held in engagement with the cam member 930 to have the cam member 930 rocked to assume the second rocking position as shown in FIGS. 13A and 13B, and a disengaging position in which the cam rocking member 970 is held out of engagement with the cam member 930 to have the cam member 930 rocked to assume the first rocking position as shown in FIGS. 15A and 15B.
The optical pickup unit 980 is supported by the frame member 910 and movable toward and away from the rotation axis of the disc retaining member 920. The optical pickup unit 980 includes a pushing end 981 and a protrusion 982 and is operative to assume three different operation states including a cam releasing state in which the optical pickup unit 980 is moved toward the rotation axis of the disc retaining member 920 with the pushing end 981 of the optical pickup unit 980 being held in contact with the cam rocking member 970 to have the cam rocking member 970 moved to assume the disengaging position as shown in FIGS. 15A and 15B, a cam holding state in which the optical pickup unit 980 is moved away from the rotation axis of the disc retaining member 920 with the protrusion 982 of the optical pickup unit 980 being held in contact with the changeover lever 990 to have the cam rocking member 970 moved to assume the engaging position through the changeover lever 990 as shown in FIGS. 13A and 13B, and a recording and reproducing state in which the optical pickup unit 980 is movable toward and away from the rotation axis of the disc retaining member 920 to record information to and reproduce information from the optical disc.
The changeover lever 990 is movable with respect to the optical pickup unit 980 to assume two different operation positions including a protruding position in which the changeover lever 990 is located on the path of the protrusion 982 of the optical pickup unit 980 to have the optical pickup unit 980 operated to assume the cam holding state as shown in FIGS. 13A and 13B, and a retracting position in which the changeover lever 990 is located out of the path of the protrusion 982 of the optical pickup unit 980 to have the optical pickup unit 980 operated to assume the recording and reproducing state as shown in FIGS. 15A and 15B.
The operation of the conventional disc drive apparatus 900 will be described hereinafter with reference to the drawings shown in FIGS. 13 to 16.
The following description will be described to the case that the optical disc is mounted on the disc retaining member 920. In this case, the disc retaining member 920 is operated to assume the non-retaining state with each of the disc holding members 940 being moved to assume the disc releasing position before the optical disc is mounted on the disc retaining member 920.
The disc retaining member 920 is held in the non-retaining state in which the optical disc is dismounted from the disc retaining member 920 as shown in FIGS. 13A and 13B until the optical disc is mounted on the disc retaining member 920.
When the optical disc, not shown, is mounted on the disc retaining member 920 with the disc retaining member 920 being operated to assume the disc retaining state, the optical pickup unit 980 is operated to assume the cam releasing state in which the optical pickup unit 980 is moved in a direction shown by an arrow 901a with the pushing end 981 of the optical pickup unit 980 being held in contact with the cam rocking member 970 as shown in FIGS. 15A and 15B.
When the optical pickup unit 980 is operated to assume the cam releasing state, the cam rocking member 970 is moved by the optical pickup unit 980 in the direction shown by the arrow 901a to assume the disengaging position in which the cam rocking member 970 is held out of engagement with the cam member 930 as shown in FIGS. 15A and 15B.
When the cam rocking member 970 is moved by the optical pickup unit 980 to assume the disengaging position, the cam member 930 is rocked by the cam rocking member 970 in a direction shown by an arrow 902a to assume the first rocking position as shown in FIGS. 16A and 16B.
When the cam member 930 is rocked by the cam rocking member 970 to assume the first rocking position, each of the disc holding members 940 is moved by the cam member 930 to assume the disc holding position in which the holding end 941 of each of the disc holding members 940 is held in contact with the central portion of the optical disc to hold the optical disc to the disc retaining member 920 as shown in FIGS. 16A and 16B.
When each of the disc holding members 940 is moved by the cam member 930 to assume the disc holding position, the optical pickup unit 980 is operated to assume the recording and reproducing state in which the optical pickup unit 980 is movable toward and away from the rotation axis of the disc retaining member 920 to record information to and reproduce information from the optical disc.
When the optical pickup unit 980 is operated to assume the recording and reproducing state, the changeover lever 990 is moved to assume the retracting position in which the changeover lever 990 is located out of the path of the protrusion 982 of the optical pickup unit 980 as shown in FIGS. 15A and 15B.
The following description will be described to the case that the optical disc is dismounted from the disc retaining member 920. In this case, the disc retaining member 920 is operated to assume the disc retaining state with each of the disc holding members 940 being moved to assume the disc holding position before the optical disc is dismounted from the disc retaining member 920.
The disc retaining member 920 is held in the disc retaining state in which the optical disc, not shown, is mounted on the disc retaining member 920 as shown in FIGS. 15A and 15B until the optical pickup unit 980 is operated to finish the recording and reproducing state.
When the optical pickup unit 980 is operated to finish the recording and reproducing state, the changeover lever 990 is moved to assume the protruding position in which the changeover lever 990 is located on the path of the protrusion 982 of the optical pickup unit 980 as shown in FIGS. 13A and 13B.
When the changeover lever 990 is moved to assume the protruding position, the optical pickup unit 980 is operated to assume the cam holding state in which the optical pickup unit 980 is moved in a direction shown by an arrow 901b with the protrusion 982 of the optical pickup unit 980 being held in contact with the changeover lever 990 as shown in FIGS. 13A and 13B.
When the optical pickup unit 980 is operated to assume the cam holding state, the cam rocking member 970 is moved by the optical pickup unit 980 in the direction shown by the arrow 901b to assume the engaging position in which the cam rocking member 970 is held in engagement with the cam member 930 as shown in FIGS. 13A and 13B.
When the cam rocking member 970 is moved by the optical pickup unit 980 to assume the engaging position, the cam member 930 is rocked by the cam rocking member 970 in a direction shown by an arrow 902b to assume the second rocking position as shown in FIGS. 14A and 14B.
When the cam member 930 is rocked by the cam rocking member 970 to assume the second rocking position, each of the disc holding members 940 is moved by the cam member 930 to assume the disc releasing position in which the holding end 941 of each of the disc holding members 940 is held out of contact with the central portion of the optical disc to release the optical disc from the disc retaining member 920 as shown in FIGS. 14A and 14B.
When each of the disc holding members 940 is moved by the cam member 930 to assume the disc releasing position, the optical disc is dismounted from the disc retaining member 920 with the disc retaining member 920 being operated to assume the non-retaining state as shown in FIGS. 13A and 13B.
The disc retaining member 920 is then held in the non-retaining state until the optical disc is mounted on the disc retaining member 920.
The conventional disc drive apparatus described in the above, however, encounters various problems as follows.
1) The conventional disc drive apparatus is increased in number of the constitution parts and thus complicated in construction, resulting from the fact that the conventional disc drive apparatus is required to comprise a plurality of spring members corresponding to the plurality of disc holding members to have each of the spring members intervene between the disc retaining member and each of the disc holding members. This means that the conventional disc drive apparatus is expensive in production cost.
2) The fact that the opposing side surfaces of each of the grooves of the cam member are spaced apart from each other at a constant space distance leads to the fact that one of the disc holding members is brought into contact with the central portion of the optical disc before the others of the disc holding members are brought into contact with the central portion of the optical disc. This means that the cam member cannot be entirely rocked to assume the first rocking position to have each of the disc holding members held in contact with the central portion of the optical disc. The conventional disc drive apparatus, therefore, cannot be operated to have the optical disc mounted thereon with a sufficient holding force to hold the optical disc.
3) The optical pickup unit is decreased in thrust force, resulting from the fact that the optical pickup unit is operated to drive the cam rocking member to be moved between the engaging position and the disengaging position. The conventional disc drive apparatus, therefore, cannot be operated to drive the optical pickup unit with a sufficient transport speed to record information to and reproduced information from the optical disc.
It is, therefore, an object of the present invention to provide a disc drive apparatus which can be reduced in number of the constitution parts and thus simple in construction.
It is another object of the present invention to provide a disc drive apparatus which can be inexpensive in production cost.
It is further object of the present invention to provide a disc drive apparatus which can be operated to have the optical disc mounted thereon with a sufficient holding force to hold the optical disc.
It is a still further object of the present invention to provide a disc drive apparatus which can be operated to drive the optical pickup unit with a sufficient transport speed to record information to and reproduced information from the optical disc.
In accordance with a first aspect of the present invention, there is provided a disc drive apparatus for driving an optical disc having a central portion formed with a central hole, comprising: a frame member, a disc retaining member rotatably supported by the frame member, a cam member supported by the disc retaining member and rockable with respect to the disc retaining member to assume two different operation positions including first and second rocking positions, a plurality of disc holding members each supported by the disc retaining member and operatively coupled with the cam member, each of the disc holding members being movable with respect to the disc retaining member to assume two different operation positions including a disc holding position in which each of the disc holding members is held in contact with the central portion of the optical disc under the state that the cam member is rocked to assume the first rocking position, and a disc releasing position in which each of the disc holding members is held out of contact with the central portion of the optical disc under the state that the cam member is rocked to assume the second rocking position, and a resilient member intervening between the disc retaining member and each of the disc holding members to have each of the disc holding members resiliently urged to assume the disc holding position.
The cam member may be formed with a plurality of grooves each having first and second groove portions, the second groove portion of each of the grooves of the cam member being larger in space distance than the first groove portion of each of the grooves of the cam member, and each of the disc holding members may have a projection slidably movably received in each of the grooves of the cam member to assume two different operation positions including a first groove position in which the projection of each of the disc holding members is located in the first groove portion of each of the grooves of the cam member under the state that each of the disc holding members is moved to assume the disc releasing position, and a second groove position in which the projection of each of the disc holding members is located in the second groove portion of each of the grooves of the cam member under the state that each of the disc holding members is moved to assume the disc holding position.
The disc drive apparatus may further comprises an optical pickup unit movably supported by the frame member, pickup driving means for driving the optical pickup unit, a cam rocking member supported by the frame member and movable with respect to the frame member to assume two different operation positions including an engaging position in which the cam rocking member is held in engagement with the cam member to have the cam member rocked to assume the second rocking position, and a disengaging position in which the cam rocking member is held out of engagement with the cam member to have the cam member rocked to assume the first rocking position, and a changeover mechanism intervening between the pickup driving means and the cam rocking member and operative to assume two different operation states including a connecting state in which the pickup driving means is operatively connected to the cam rocking member through the changeover mechanism to have the cam rocking member moved between the engaging position and the disengaging position, and a disconnecting state in which the pickup driving means is disconnected from the cam rocking member.
The disc drive apparatus may further comprises a cam rocking member supported by the frame member and movable with respect to the frame member to assume two different operation positions including an engaging position in which the cam rocking member is held in engagement with the cam member to have the cam member rocked to assume the second rocking position, and a disengaging position in which the cam rocking member is held out of engagement with the cam member to have the cam member rocked to assume the first rocking position, a driving lever supported by the frame member and operatively connected to the cam rocking member, the driving lever being movable with respect to the frame member to assume two different operation positions including a first driving position in which the driving lever is operative to drive the cam rocking member to be moved to assume the engaging position, and a second driving position in which the driving lever is operative to drive the cam rocking member to be moved to assume the disengaging position, and lever urging means for urging the driving lever to assume the second driving position.
The disc drive apparatus may be available for a video recorder for recording information to an optical disc driven by the disc drive apparatus.
In accordance with a second aspect of the present invention, there is provided a disc drive apparatus for driving an optical disc having a central portion formed with a central hole, comprising: a frame member, a disc retaining member supported by the frame member and rotatable around its rotation axis, the disc retaining member having a shaft portion in the form of a cylindrical shape, and a retaining portion integrally formed with the shaft portion of the disc retaining member and radially outwardly extending from the shaft portion of the disc retaining member, a cam member having a rock axis held in coaxial relationship with the rotation axis of the disc retaining member, the cam member being supported by the disc retaining member and rockable around the rock axis of the cam member to assume two different operation positions including first and second rocking positions, the cam member being formed with a plurality of grooves each having a first groove portion close to the rock axis of the cam member, and a second groove portion remote from the rock axis of the cam member, a plurality of disc holding members each supported by the disc retaining member and operatively coupled with the cam member, each of the disc holding members having a holding end and being movable with respect to the disc retaining member to assume two different operation positions including a disc holding position in which the holding end of each of the disc holding members is held in contact with the central portion of the optical disc under the state that the cam member is rocked to assume the first rocking position, and a disc releasing position in which the holding end of each of the disc holding members is held out of contact with the central portion of the optical disc under the state that the cam member is rocked to assume the second rocking position, each of the disc holding members having a projection slidably movably received in each of the grooves of the cam member to assume two different operation positions including a first groove position in which the projection of each of the disc holding members is located in the first groove portion of each of the grooves of the cam member under the state that each of the disc holding members is moved to assume the disc releasing position, and a second groove position in which the projection of each of the disc holding members is located in the second groove portion of each of the grooves of the cam member under the state that each of the disc holding members is moved to assume the disc holding position, and a resilient member intervening between the disc retaining member and each of the disc holding members to have each of the disc holding members resiliently urged to assume the disc holding position.
Each of the grooves of the cam member may have opposing side surfaces each held in parallel relationship with the rock axis of the cam member, each of the grooves of the cam member having a center plane located between the opposing side surfaces of each of the grooves of the cam member in equidistantly spaced relationship with the opposing side surfaces of each of the grooves of the cam member, and a perpendicular line held in perpendicular relationship to the center plane of each of the grooves of the cam member, the opposing side surfaces of each of the grooves of the cam member opposing and spaced apart along the perpendicular line of each of the grooves of the cam member from each other at a predetermined space distance.
The second groove portion of each of the grooves of the cam member may be larger in space distance than the first groove portion of each of the grooves of the cam member.
The disc drive apparatus may further comprises an optical pickup unit having a moving line held in perpendicular relationship to the rotation axis of the disc retaining member, the optical pickup unit being supported by the frame member and movable toward and away from the rotation axis of the disc retaining member along the moving line of the optical pickup unit, a pickup driving motor for driving the optical pickup unit to be movable toward and away from the rotation axis of the disc retaining member along the moving line of the optical pickup unit, a cam rocking member supported by the frame member and movable with respect to the frame member to assume two different operation positions including an engaging position in which the cam rocking member is held in engagement with the cam member to have the cam member rocked to assume the second rocking position, and a disengaging position in which the cam rocking member is held out of engagement with the cam member to have the cam member rocked to assume the first rocking position, and a changeover mechanism intervening between the pickup driving motor and the cam rocking member and operative to assume two different operation states including a connecting state in which the pickup driving motor is operatively connected to the cam rocking member through the changeover mechanism to have the cam rocking member moved between the engaging position and the disengaging position, and a disconnecting state in which the pickup driving motor is disconnected from the cam rocking member.
The disc drive apparatus may further comprises a cam rocking member supported by the frame member and movable with respect to the frame member to assume two different operation positions including an engaging position in which the cam rocking member is held in engagement with the cam member to have the cam member rocked to assume the second rocking position, and a disengaging position in which the cam rocking member is held out of engagement with the cam member to have the cam member rocked to assume the first rocking position, a driving lever supported by the frame member and operatively connected to the cam rocking member, the driving lever being movable with respect to the frame member to assume two different operation positions including a first driving position in which the driving lever is operative to drive the cam rocking member to be moved to assume the engaging position, and a second driving position in which the driving lever is operative to drive the cam rocking member to be moved to assume disengaging position, and a lever urging member intervening between the frame member and the driving lever to have the driving lever resiliently urged to assume the second driving position.